1. Field of Invention
The present invention relates to crack sealant packaging and methods of packaging crack sealant and using the same.
2. Description of Related Art
“Crack sealant” is general term for materials which are used to fill and thereby seal cracks and joints in asphalt and cement pavement surfaces. Crack sealant materials are sometimes also referred to in the art by terms such as, for example: hot pour; crack seal; crack sealer; crack sealant; crack fill; crack filler; joint seal; joint sealer; joint sealant; joint fill; joint filler; rubberized asphalt; tar; polymer-modified asphalt; thermoplastic-modified asphalt; para-plastic materials; rubber-modified asphalt; traffic loop detector sealant; waterproofing membrane asphalt; modified asphalt; roofing asphalt; cold joint adhesives; marker adhesives; and other asphalt/resin/polymer compositions. Throughout the present specification and in the appended claims, the term “crack sealant” will be used exclusively, but the term should be understood to encompass all materials having the same general composition, use and/or properties. Crack sealant is widely used to fill and thereby seal cracks and joints in highways, streets, parking lots and driveways from water penetration. The use of crack sealants prolongs the service life of such pavement surfaces.
Crack sealant formulations vary widely depending upon manufacturer and depending upon the particular end use application for which they are intended. In general, crack sealants are composed of base asphalt (bitumen), polymer/rubber copolymers (e.g., styrene-butadiene-styrene copolymers), extenders and reinforcing fillers. At most ambient storage and transportation temperatures, crack sealant compositions tend to be in solid form. At the time of use, crack sealants are heated to temperatures whereby they become a molten liquid and are then applied in a heated liquid form by pouring and/or pumping. The molten liquid seeps into and fills the cracks and joints and then, upon cooling, re-solidifies within the cracks and joints thereby sealing/filling same.
Most crack sealant material is supplied to end users in poly bag-lined, rectangular corrugated boxes. At the time of manufacture, the corrugated box is lined with the poly bag. Molten crack sealant material is poured into the poly bag-lined corrugated box. Once the desired amount of crack sealant (e.g., 20-60 lbs.) has been poured into the poly bag lining the corrugated box, the crack sealant composition is permitted to cool, whereupon it solidifies and takes the rectangular shape defined by the interior space of the corrugated box.
Packaging of this type provides certain advantages and disadvantages. Advantageously, the rectangular corrugated packages can be stacked on pallets and shipped to job sites. The corrugated packages provide a flat surface, which can bear identification information. At the time of use, the poly bags containing the crack sealant can be withdrawn from the corrugated box and inserted into the melting equipment together with the crack sealant material, with the poly bag melting and becoming part of the molten end use material. The corrugated boxes can be recycled.
Disadvantageously, the corrugated boxes must be collected at the job site for recycling. In blustery conditions, the empty corrugated boxes can be blown away from their intended staging location. In wet conditions, the corrugated boxes can break down before or after the crack sealant has been used. And, the corrugated boxes are susceptible to damage (e.g., deformation) due to compression (e.g., from the weight of the material itself, when stacked).
Alternative crack sealant packaging is available in the marketplace. For example, Maxwell Products Incorporated of Salt Lake City, Utah supplies crack sealant packaged within a thermoplastic container that comprises an expanded polymer (expanded polystyrene). Upon information and belief, applicant believes such packaging is described in U.S. Pat. No. 8,017,681 to Guymon et al. Packaging of this type provides certain advantages and disadvantages. The principal advantage is that the expanded polymer “shell” surrounding the crack sealant material can be inserted into the melting equipment together with the crack sealant material, with the expanded polymer melting and becoming part of the molten end use material. This means that it is no longer necessary to stage corrugated boxes at the job site for later recycling. Another advantage is that the expanded polymer “shell” is somewhat water resistant, which allows it to be stored in wet environments for short periods of time. Disadvantageously, containers of this type are relatively expensive as compared to corrugated boxes, require much more storage and transportation space (i.e., the packaging has much thicker bottom, top and sidewalls as compared to a corrugated box), and can become damaged if mishandled due to the inherent fragility of expanded polystyrene. Furthermore, due to the thickness of the containers, less crack sealant can be delivered to the melting equipment per charge.
Crafco Inc. of Chandler, Ariz. markets crack sealant in meltable packaging under the PLEXI-MELT™ brand. Upon information and belief, such product consists of a rectangular block of solidified crack sealant disposed in a poly bag, which is overwrapped with and thereby enveloped within a non-woven fiber packaging film material that is the same as or similar to the non-woven polyethylene packaging material available from DuPont Industrial Packaging under the TYVEK® brand. Advantageously, the non-woven packaging film material surrounding the crack sealant material can be inserted into the melting equipment together with the crack sealant material, with the non-woven packaging film material melting and becoming part of the molten end use material. Again, this prevents the need to stage corrugated boxes at the job site. Another advantage is that the non-woven packaging film material is somewhat water resistant, which allows the product to be stored in wet environments with less concern that water will damage the container as compared to conventional corrugated box packaging. Furthermore, the wrapping is substantially thinner, by comparison, than meltable expanded polymer packaging. Disadvantageously, containers of this type are relatively expensive as compared to corrugated boxes, are somewhat difficult to handle (they are more slippery than cardboard boxes) and, the packaging material can become brittle after prolonged exposure to sunlight.
There is a substantial need for improved meltable crack sealant packaging.